Such release ski bindings are described in German Pat. No. 2 533 337. In these conventional ski bindings, the spring of the holding mechanism acts through a piston onto an approximately mushroom-shaped follower member, which is supported swingably to all sides in the housing of the holding mechanism. The stem portion of the mushroom-shaped follower member is received in a recess of a ski-fixed fitting. In these known ski bindings, the ski shoe is held at its tip or toe by means of a rigid bar on the sole plate. In the case of a fall of the skier to the rear, the ski shoe is therefore released only with great difficulty.
This disadvantage is avoided in the ski binding according to German Pat. No. 2 324 078, however, this binding is very complicated in its design. That is, the release mechanism is housed in the space between the base plate and the sole plate. This, however, requires special seal structure to prevent the penetration of snow and dirt therein. Furthermore, the mounting is complicated and expensive.
The goal of the invention is to overcome the disadvantages of the conventional designs and to provide a release ski binding of the above-mentioned type, which is simple in its design and permits a very exact adjustment of the desired release moment during a frontal fall and during a twisting fall.
This goal is inventively attained primarily by providing a locking mechanism having two clamping jaw pairs which laterally engage the ski shoe and which are constructed as two-arm levers, are supported on the sole plate and can be moved into the clamping position by a slide-member plate which is guided on the sole plate and is provided with wedge-shaped shoulders, whereby the slide-member plate is coupled by means of a control lever having a stepping bar which is supported on the sole plate.
The concept of supporting one-arm clamping jaws, which laterally engage the ski shoe, on a sole plate and to move same through a slide-member plate with the help of wedge-shaped shoulders into the clamping position is actually already known through the teachings in German OS Nos. 2 943 209 and 3 026 918. However, in these constructions, the locking spring acts directly onto the clamping jaws, the load of which is utilized for the involuntary or automatic release of the ski binding, and brings about certain inexactnesses compared with the ski bindings of the above-mentioned type in which the angle of traverse of the sole plate is decisive for effecting the opening of the locking mechanism.
Furthermore, it is no longer new to use stepping bars in ski bindings (compare U.S. Pat. No. 4,312,517). However, in the known ski binding the stepping bar is only used to swing during a stepping in procedure wherein the ski shoe effects a movement of the two braking mandrels from their braking position upwardly over the plane of the upper surface of the ski and at the same time to align the ski shoe both in the longitudinal direction and also in the transverse direction of the ski. An operation of the holding elements for the ski shoe by action of the stepping bar does not take place in this construction.
Furthermore, the invention provides that the axle for the stepping bar is arranged in the end region of the sole plate, closest the tip of the ski. This causes the stepping of the ski shoe into the ski binding to be simplified inasmuch as the relative movement between the tip of the ski shoe and the ski, compared with the reversed arrangement (arrangement of the stepping bar axle on the end of the sole plate remote from the tip of the ski), is substantially reduced.
Furthermore, the control lever is inventively constructed as a two-arm lever supported on the sole plate and the upper end of which is guided by means of a roller in guideways provided on the underside of the stepping bar. This enables a large amount of leverage to be achieved and with it the force, which is necessary for the adjustment of the slide-member plate, can be substantially reduced.
According to another characteristic of the invention, the lever arm of the control lever, which lever arm lies opposite the roller, is constructed fork-shaped and is provided with two inner prongs and two outer prongs. Through this construction the function which is to be carried out by the control lever is divided into two pairs of elements, whereby the one pair is to cause only the movement of the slide-member plate toward the tip end of the ski, the other pair, however, causing first an adjustment of the slide-member plate toward the tip of the ski and thereafter a sudden movement of the slide-member plate rearwardly into the clamping position.
In order to make the opening of the ski binding easier, two bearing blocks are inventively secured to the upper surface of the slide-member plate, in which bearing blocks a bolt is movably guided in the longitudinal direction of the ski, which bolt is under the influence of a spring urging it toward the tail end of the ski. A further characteristic of the invention is to provide the control lever with a nose at its end which carries the roller, which nose serves as a load bearing place against which the bolt rests in the skiing position of the ski binding.
Of course it would be possible to provide the slide-member plate with shoulders for the engagement of the two prong pairs. However, it is preferable that the slide-member plate be provided with a hole located between the bearing blocks, which hole is preferably approximately T-shaped in the top view, into which hole, in the stepping-in position of the ski binding, is received the four prongs of the control lever.
Furthermore, it is provided inventively, that the slide-member plate is releasably connected to the resilient holding mechanism through at least one one-arm locking lever, which holding mechanism, is housed in a housing on the sole plate. According to this characteristic, a retaining spring is utilized for loading the slide-member plate. The spring thus has to fulfill two functions simultaneously. This brings about a certain simplification of the construction. It is thereby preferable for the slide-member plate to be constructed fork-shaped at its end which is adjacent to the holding mechanism and supports a roller thereon on each forked prong. The roller, in the skiing position of the ski binding, rests on a shoulder of the associated locking lever, which shoulder extends transversely with respect to the longitudinal axis of the ski. The two rollers substantially increase the exactness with which the ski binding opens during the adjusted release moment, since the friction between the slide-member plate and the two locking levers is substantially reduced by the rollers.
In a ski binding wherein the holding mechanism includes a mushroom-shaped follower member, the enlarged head of the follower member is supported swingably to all sides in a hole in a wall of the sole plate. The follower member is held in the normal position under the influence of a piston which is loaded on one side thereof by the release spring and with its stem received in a ski-fixed fitting. A bolt or pin extends through the piston, the ends of which bolt are guided in slotted holes in the wall of the sole plate. The legs of an approximately U-shaped intermediate lever, is supported in the housing on the sole plate and engage under the influence of a torsion spring the ends of the bolt. The ends of the bolt project laterally beyond the slotted holes in the wall and operatively engage each leg of the intermediate lever. A reliable coupling of piston and locking lever is brought about in this manner. This effect is also desired by a further characteristic of the invention, namely, that for coupling of the intermediate lever with each locking lever, the first supports an axle thereon, which axle is guided in a slotted hole which extends in the longitudinal direction of the locking lever.
In order to facilitate a manual release of the ski binding in a simple manner, the invention includes the provision that at least one link member has one end arranged on the axle and the other end hingedly connected to a two-arm release lever which is supported on the housing of the sole plate.
Also a direct loading of the piston associated with the follower member by the spring of the holding mechanism would principally be conceivable. However, in order to permit a very sensitive adjustment of the initial spring tension, a one-arm lever is inventively supported on the axis for the intermediate lever, which one-arm lever rests with a cam on the piston in the hole of the sole plate and on the oppositely lying side is loaded by the spring of the holding mechanism. It is thereby preferable, if the release spring is housed in a spring housing which is pivotal about the axis of the axle for the locking lever so that the axle is movable approximately in the longitudinal direction of the ski in at least one slotted hole in the housing. Furthermore, it is provided that in the center area of the spring housing, bearing pins are connected thereon, on which bearing pins are supported two laterally spaced two-arm levers, the lower ends of which are connected through a rotatably supported bolt and the upper ends of which are supported on a support wall in the housing, which support wall extends at least approximately parallel with respect to the upper surface of the ski. The bolt has a threaded hole therein which extends transversely with respect to the bolt axis, into which threaded hole is threadedly engaged an adjusting screw, the end of which is supported for example by means of a flange on the inner side of the spring housing. This development makes it possible to maintain constant the relationship of the initial tension of the locking spring at the start of the elastic range and at the release point even when the initial tension of the locking spring which is active at the start of the elastic range is changed by means of the adjusting screw.
In order to also permit in the region of the spring housing a transfer of the spring force without large friction losses, a piston, which is loaded by the release spring, is guided in the spring housing, which piston has a roller on the side thereof remote from the release spring. The roller is adapted to rest on the lever.
Finally, it has been proven to be particularly preferable for the manufacture of the ski binding, if the slide-member plate consists of at least two plate-shaped parts, which receive the wedge-shaped shoulders therebetween them and are connected to one another by plural rivets or the like.